The most common side effects of Xeljanz include upper respiratory tract infection, cold-like symptoms, diarrhea, rash, herpes zoster infection (shingles) and headache. The medication can also cause more severe problems such as serious infections, heart problems, cancer, blood clots, and death.
Xeljanz and Xeljanz XR are Janus kinase (JAK) inhibitors that treat rheumatoid arthritis, psoriatic arthritis and ulcerative colitis by regulating the activity of the immune system. Tofacitinib is the active ingredient in the drug.
Most of the drug’s common side effects are minor and range from headaches to cold-like symptoms. But the drug also carries several black box warnings for serious infections, blood clots, increased risk of death and malignancies such as lymphoma.
Between 2013 and 2018, the FDA Adverse Events Reporting System (FAERS) received 42,528 reports of adverse reactions for the two drugs. Of these, 14,679 were serious and 983 involved deaths.
The data from FAERS are self-reported, and the U.S. Food and Drug Administration cannot verify if they are accurate. But the agency will sometimes use them to determine if it should get more data on certain adverse effects.
the FDA released a safety communication to alert the public that a safety trial found an increased risk of blood clots in the lungs and death among people with rheumatoid arthritis who took a dose of 10 mg twice daily – a dose that is higher than approved. After this communication went public, lawyers began investigating lawsuits against Pfizer.
the FDA issued a Drug Safety Communication alerting the public that initial safety trial results linked Xeljanz to an increased risk of cancer and serious cardiovascular events. The most common cancer was lung cancer and the most common heart problem was heart attack, according to Pfizer’s data.
After further investigation, the FDA determined that lower and higher doses of Xeljanz side effects increased the risk of “serious heart-related events such as heart attack or stroke, cancer, blood clots, and death” according to the agency’s September 2021 Safety Communication. In December 2021, Pfizer updated the black box warning to include this information.
While most side effects in clinical trials were not severe, the medicine does have a few serious risks. Some patients shouldn’t take the drug and some might be at higher risk of side effects. Doctors should monitor white blood cell counts, hemoglobin levels, liver enzymes, and cholesterol levels.